The present disclosure is related generally to the fabrication of semiconductor devices, and, more particularly, to a metal-insulator-metal (MIM) structure, a method of manufacturing the structure, and a semiconductor device incorporating the structure.
Capacitors are components for many data manipulation and data storage applications. In general, capacitors include two conductive electrodes on opposing sides of a dielectric or other insulating layer, and they may be categorized based on the materials employed to form the electrodes. For example, in a metal-insulator-metal (MIM) capacitor, the electrodes are substantially metal. MIM capacitors offer the advantage of a relatively constant value of capacitance over a relatively wide range of voltages applied thereto. MIM capacitors also exhibit a relatively small parasitic resistance.
Generally, to minimize the size of MIM capacitors cup-shaped capacitor structures, located in capacitor openings, are used. The capacitor opening is etched through a stop layer to expose a contact plug thereunder, and over-etching is performed to ensure the capacitor opening is fully defined in every cell areas over a semiconductor wafer. When there is an overlay shift of the capacitor opening, the over-etching produces a micro-trench under the capacitor opening which may adversely affect reliability.